v.1. To mix something before cooking or use: You must stir up the concrete thoroughly before you start paving the path. I poured the batter into a bowl and stirred it up vigorously.
2. To churn or agitate something into a state of turbulence: The storm stirred up the normally placid lake. The wind stirs the leaves up.
3. To cause something to form by churning or agitating: The truck zoomed off, stirring a cloud of dust up behind it. I stirred up a batch of concrete in the mixer and got to work paving the driveway.
4. To rouse the emotions of someone or something; excite someone or something: The protesters hope to stir up the public through this demonstration. The teacher stirred the students up when she threatened to give them more work.
5. To summon some collective emotion or sentiment by exciting a group of people: The court's verdict was certain to stir up controversy. The tourism board is trying to stir up interest in the city.
6. To evoke some mental image or remembrance: That old picture stirs up many memories for me.